Tenji is pleased to present a series of exclusive articles for Reef2Reef members. We will be delving into the various aspects of reef keeping, focusing on tried and true methods that can be implemented by aquarists of all levels.
After we have chosen our display aquarium and sump, it’s time to start planning the life support system (LSS). Protein skimmers are the digestive tract of our LSS. They remove waste, excess food and other organic compounds prior to breaking down into algae fuel. The pump is the heart of your protein skimmer. A quality handcrafted acrylic reaction chamber fitted with an el cheapo pump won’t get you far. Go the extra mile when it comes to budgeting for your skimmer to avoid premature failure and constant tinkering. Once your skimmer is dialed in you should be able to forget about it (besides regular cleaning) for a while.
A quick internet search will reveal a myriad of options. We’re pleased to see that nowadays most off-the-shelf skimmers are actually pretty great right out of the box. Gone are the days of upgrading impellers, improving needle-wheel performance, and injecting additional air into the reaction chamber. That’s not to say there aren’t a few duds still being floated as new technology, so stick with a known brand with consistent good reviews and you’ll start off on the right foot.
Due to the emotionally charged arguments that go hand and hand with foam fractionator choices we will not be bulleting pros and cons, rather providing a brief description of each method.
Needlewheel impeller skimmers are by far the most prevalent today. And for good reason, they’re generally quite easy for the uninitiated to tune, they’re a bit more forgiving when it comes to settings than their counterparts, and quality models just keep running with little interference from the aquarist. From tiny to massive, they can be found in many shapes and sizes. Did I mention they use the least power out of the other options too? Besides perhaps the age-old classic air driven skimmers, needlewheels quietly sip watts as the impeller design does all the heavy lifting. Needlewheels pull air into the pumps’ volute via a venturi, then shred the air into microbubbles that rise up the reaction chamber. These microbubbles strip hydrophobic molecules out of solution and eventually into the collection cup (same as all skimmers we’ll discuss today).
Air driven counter-current skimmers (for home aquariums) are nearly obsolete. We find them in the back closets of public aquariums that employees forgot existed. They can be spotted at the occasional garage sale alongside a slate-bottomed steel-framed aquarium (vintage aquariums FTW). But in their day, they were the bee’s knees. These skimmers used wooden air stones to create microbubbles, which operate best when like-new. This resulted in replacing the wooden air stones every couple of months. Water is generally pumped into the top and exits out the bottom, so the air bubbles driven up would create a counter-current.
Beckett skimmers can be defined similarly to a downdraft skimmer (see below), however, they utilize a special injector called a, wait for it… Beckett injector. Like any venturi, the Beckett injector draws air into water by utilizing a change in pressure. Beckett injection is simply a specific way of drawing in that air. Some swear these skimmers produce the most consistent and tiniest bubbles, and generally, the reaction chamber is smaller than a standard venturi model. Our main gripe with them compared to other methods nowadays is that they oftentimes require a pressure-rated pump to afford proper operation of the injectors, which can draw major power long-term. With that said they are a truly phenomenal means of creating skimmate.
Downdraft skimmers can still be spotted in the field on occasion. Another oldie but goodie, with some companies still pushing out downdraft powerhouses that send many needlewheels running for the hills. As opposed to a beckett or venturi skimmer, downdraft skimmers force water through a nozzle into an inlet commonly filled with bioballs (or another turbulence creating mechanism). As the high-pressured water tears through the nozzle and flows downward, microbubbles are formed. The micro bubble filled water collects in a square or rectangle basin at the bottom then moves upward into the reaction chamber. Best performance of a downdraft skimmer also generally requires a pressure-rated pump, but once these get going, they just don’t quit.
More often than not you’ll find yourself staring at a needlewheel skimmer when you pop a fellow reefers hood, but don’t be too quick to write off the other styles. Due to the influx of el cheapo mass-produced needlewheel skimmers, you’ll commonly find higher quality versions of the other styles at rock bottom prices. Choose a skimmer that you’re not afraid to take apart for consistent cleaning and preventative maintenance and be comfortable with the fine-tuning process.
Remember skimmers are the digestive tract of your system, likely the most important piece of equipment to keep nutrients at bay. You get what you pay for no matter the philosophy behind it, so don’t skimp!